Casein versus Cascamite - a post you'll be glued to!

Casco glue tinWhen straw bale building, one inevitably ends up with lots of wood that needs both gluing and nailing together. But what glue should a natural builder use?

Where there is a need for exterior grade glue and certainty that the fix will not be compromised over time, the current glue you frequently see being used is Cascamite. This is a synthetic, urea-formaldehyde glue that generally comes in powder form for mixing on site.  You may also hear of phenol formaldehyde glues like Resorcinol.

And formaldehyde is bad, right? Well, yes. And no. Formaldehyde is naturally occurring (and companies also make it).  It can be found in small amounts in fruits, vegetables and all sorts of stuff, including us.  And, like many things in life, that's the thing - small quantities can be okay, but larger quantities can start causing problems.  This informative American Cancer Society article suggests the presence of formaldehyde in the air at anything greater than 0.1 parts per million can result in some folk experiencing irritation.  This could be an itchy nose, watery eyes, a burning sensation in the eyes, nose, throat etc.  Because these reactions are very similar to those for all sorts of other illnesses it can be hard to pinpoint formaldehyde as the cause, but it's certainly one of those things some people are more susceptible to.

Formaldehyde off-gases, i.e. once it is manufactured and put into a material there is a period of time when it will put out more formaldehyde into the atmosphere than it will afterwards.  When added formaldehyde is used in building products it ups the concentration and problems are more likely to occur.  Simple choices when specifying materials can mitigate the formaldehyde risk, and minimise the extra chemicals you're buying and furthering the use of, perhaps unwittingly.  For example, we use a lot of oriented strand board in straw bale structural beams.  We always use Smartply OSB3 because it contains no added formaldehyde, whereas I believe Sterling board and other makes do use extra formaldehyde in the manufacturing process (I am happy to be told otherwise!).  This article from the US points out how important the need for research into finding an effective and more sustainable alternative to formaldehyde based glues in board manufacturing is becoming.

Cascamite glue tubSo.  What about the glue.  What's the point of using Smartply if you're going to stick it together with a formaldehyde glue? Aren't you undoing all your good work? Well, certainly partially, yes.  I'm no scientist and I've love to hear arguments for and against but, perhaps not surprisingly, I'd much rather use something else.  I understand wool insulation sequesters free formaldehyde, and because we often use that inside the glued beams then that possibly mitigates off-gassing to some degree, but I've seen no real scientific evidence.

What we need is a fantastic natural wood glue.  Apparently there are no natural wood glues that are not degraded by water in some way, so full-on external use might be difficult, but what about some research on the limits of what does exist?

There are actually several really good natural glues, and for building purposes I think the absolute best is casein glue.  Casein glue is made from milk and humans have used it for thousands of years.  It's amazingly good glue!  I'm desperate to do some casein glue experiments and if anyone else is interested, or knows of any good casein glue resources, I would love to hear from you!  For further comparison, this page mentions casein glue, along with the formaldehyde ones.

And this kind of brings us full circle.  Cascamite was born out of the rapidly expanding chemical industry of the mid 20th century.  I found this amazing article from the February 1941 issue of Popular Science magazine (from the US - the advertisements are as much fun as the articles!).  I'd never really made the naming connection between CASein and CAScamite.  It turns out the 'Casein Company', as a producer of casein glue in the US - branded Casco - was looking to chemicals to make better glues (chiefly more waterproof ones).  And consequently Cascamite lives - and Casco died.  I wonder if we can see a revival of casein glue?  I for one am prepared to stick with it.

Check out this recipe and project for casein glue and let me know how you get on!

Self-build discussed on Radio 4's Thinking Allowed

Laurie taylor - Thinking Allowed - BBC Radio 4There was an interesting piece about self-build recently on Radio 4's Thinking Allowed programme.  You can access it on the BBC website here - it's on for about the first 10 minutes.

Host Laurie Taylor and guest Michaela Benson discuss the motivations and experiences of UK self-builders that she has gathered in her research.  She discusses this and other interesting self-build things on her research project's blog.

Michaela aslo mentions Jenny Pickerell's green-building research, which seems to be discussed on Jenny's blog here.  All good reading!

I really like this piece because it backs up the way we intuitively work as a company.  There is a real need for help and support for self-builders in the UK and we understand how stressful and what a massive step taking on and accomplishing any building project can be - especially building a home.  Self-build can be a hugely life-affirming and empowering experience if done well, however managing the build process well is absolutely key.  We are happy to take on the management of your building project, whilst keeping you as immersed and involved in it as you'd like to be.  The ambition is to give you the wonderful experience of self-build without all the headaches.  Some people, of course, are keen to take on the challenge of managing an entire build, and if that's the case we can do our very best to fit in with your plans.

The self-build part in the Radio 4 piece above is also followed by an interesting, yet rather sad and shocking piece about evictions. However, the guest, Professor Matthew Desmond, sounds like he might be related to Professor Denzil Dexter from The Fast Show, which made me chuckle. :-)

A glimpse into the mind of a straw bale builder...

Phil Christopher and straw bale wallWhen I was young I wanted to do a lot of different things, but the core ambition was always to do something that would help our environment, not make it worse. To find and promote ways to 'live lightly' and co-exist with the rest of nature - the lack of which, for all the positives of human progress, seems to me to be our kind's biggest failing. Even though I've always 'done my bit', when it came to work I eventually got trapped in the rat race for many years, ending up working in IT as a systems developer at Bournemouth University, sitting at a desk. A few years ago, a moment of clarity got me thinking that there should be more to life than that (no offence IT!), so I started retraining to do something I really wanted to do.

Having always been a practical person, I started thinking about the building work I'd done throughout my life and how it was something I'd always enjoyed. You get that sense of 'flow' with hands on work - and it's good fun to work with other like-minded people to do something good. So for several years now I've been studying and retraining in 'natural' or 'sustainable' building. (There never seems to be the right word to describe us pioneer builders and I look forward to the day we can all just call it 'building'!)

I read some research a few years ago that compared IT project management to construction project management. It said job satisfaction was always higher in construction project management because building materials are tangible and you know what goes where, unlike IT, where things are virtual and aren’t as easily designed or implemented. That got me thinking about building as a career and the project management skills I had have proved to be highly transferable. And having made the switch I can confirm that job satisfaction is definitely much higher! I managed to take a career break from work for a few months to start Huff and Puff Construction, and as well as immersing myself in the ways of straw bale and natural building, I did several other courses, from coppice crafts to dry stone walling, and made a point of talking to friends in building, landscaping etc. about what the work was like. Personally I found it useful to get a taste of lots of different skills and trades so I’d know what I was dealing with in business. And a big part of natural building and renovation is knowing what materials to specify. The straw, timber and lime and clay plasters are the easy bits. Knowing if you want to specify low smoke zero halogen electrical cable and polypropylene conduit instead of PVC (which we do), or to use something like Fermacell board instead of new plasterboard (if the client really wants that kind of finish) involves some effort working out and sourcing.

The training never ends and it's fascinating! We have lost - or nearly lost - so much information about how we used to build before modern cement. And modern cement (which does have the occasional use) has generally been a disaster in our building fabric and is a bigger disaster for our climate. Traditional materials such as lime and clay work 'with' buildings. They are mostly weaker than the materials they glue together, like brick and stone, which means buildings can actually move, without failing. They are also breathable, whereas cement traps water and has been responsible for destroying many a fine building with its overuse. Globally, cement production alone accounts for 5-10% of global manmade CO2 emissions. Where we don’t need it, we shouldn’t be using it. That easily covers most housing under three stories.

Which brings me on to straw. Straw - and reeds and other similar materials - have been used in buildings and shelters the world over for as long as we’ve existed. With the vast amount of arable crops we grow we have more straw than we know what to do with. In the UK alone, we could build at least half a million houses each year from surplus straw. And like trees, straw captures carbon when it grows. Unlike trees, straw grows every year. Lock that straw up in a building for 200 plus years and we’re making a massive contribution to carbon capture - with no massively complicated technology required.

And that’s the beauty of building with straw. There are details to learn, like any other craft, but it’s inherently simple. Everyone can have a go without breaking the bank. This doesn’t translate well to our corporate world, of course, where a big company always has to make big bucks. A system where things are made more complicated to make sure individuals can’t do things for themselves. So, buck the trend. Get natural, get local, get your hands dirty and let’s do it for ourselves!

That’s what natural builders believe in. Of course, the reality at the moment is that creating a green and ethical business often feels like trying to put as many hurdles in the way of success as you possibly can. Success as it’s currently defined, of course. I can hear big shot investors laughing… "Who wants to invest in a building business that doesn’t believe in getting a cut for as many middle men along the way as possible, at the customer’s expense?”, "Natural builders must all be mad!”

But I believe we will prevail, because we have a much broader definition of success. We teach, we empower people, we make people smile, we get people of all ages and types working together and we end up with beautiful, breathable, insulating, planet-saving buildings that people can enjoy. And we can do it cheaper than those ugly, over-priced, under-insulated boxes that are currently on sale everywhere. I am sure we will prevail, because even though the current system is rigged against us, we offer a chance of something better.


Housebuilding styles - history - future

fresco_secco_01When I started writing this post I was sitting in a wonderful 18th century villa on the shore of Lake Garda.

One thing that struck me about the buildings around Garda is how different some of the construction styles are to back home in the UK.  No brick on show, everything is rendered - and often painted to imitate stonework, or with frescoes/seccoes.  The roofs are made of semi-circular 'barrel' tiles (perhaps the oldest style of clay tile there is?) laid alternately up and down, to allow the water to drain down, and the roof pitches are shallower, presumably in part to stop the whole lot sliding off.  Having noted the lack of brick, we visited Verona on our way back and interestingly some of the highest status buildings there are made almost entirely of red brick.

italian_tilesEvery time I travel (which isn't often) I am always struck by these differences in architecture from one country or region to another.  I like the idea that we can always learn from what other people do, and whilst construction techniques that are appropriate in northern Italy might not be so at home, some might be, and these ideas don't travel very easily I think.  People are taught to build in a certain style in whatever country or area they are, and in the UK our current mainstream methods of training reinforce this.

However, sometimes we need to take a bit of a leap of faith, of imagination.  This might be in response to environmental or social changes.  Sticking with the old might not be such a good thing. Interestingly, of course, a lot of new construction methods were brought to the UK by the Romans - roof tiles for one, I think - and then some methods had to be adapted or abandoned because the climate here was so different.

Such upheaval in building methods doesn't happen very often.  We've been building with natural materials - straw, wood and stone etc. - for as long as we've been able to.  A few of the more recent UK milestones are probably other Roman introductions like varieties of concrete (with lime, not the modern version), glass, and even more recently industrial quantities of modern clay bricks, modern cement and structural iron and steel.

verona_arenaHousebuilding in the UK is currently in need of a leap of faith.  Apart from the fact most housing estates being built are soulless boxes - the ubiquitous 'modern townhouse', often with tiny rooms, small gardens and no focus of community (in fact an emphasis on shutting it out) - the method of construction itself has had its time.  The cavity wall, often thought to be the best thing since sliced bread, is refusing to die.  And it needs to.  Originally invented to keep the load bearing inner walls of the house protected, it has become apparent it's a really good way to lose heat in winter. Now we put insulation in the gap, but not very much.  It doesn't work very well, the whole concept is a bit of a bodge, so why do nearly all new houses get built this way? That would be a good question for both the major housing developers and government, and we'll endeavour to examine that in much more detail sometime soon, but basically it's because that's what we train people to build.

verona_brickSo what are the alternatives?  What new building methods could be more sustainable and better address our current issues of a changeable climate and sky-rocketing prices for heating?  Well, let us consider timber and straw.  Timber houses arecurrently not that common in the UK, even though we have quite good access to decent local timber wherever we are. You don't have to go very far at all to find a field full of wheat or any of the arable crops from which straw is a useful leftover.  But why would we even think about choosing timber and straw now we have brick?  Well this is where we come back to environmental and social changes.  Timber and straw houses are inherently excellently well insulated.  As with any exceptionally well insulated building, heat and cold take longer to come in and go out, therefore the building is warm in winter with little extra heating, and cool in the summer.  If you have eve worked out how much you spend on heating in any given year in an average house, you will know you don't have to start saving much for those numbers to be quite significant.

Straw and timber - which I have just cunningly decided to refer to as 'strimber' - ticks all the right boxes for both construction and sustainability.  Quality, sustainable timber and straw here in the UK means that you could easily build a whole house - a warm and beautiful house - made from materials within a few miles of your site.  This isn't that surprising because that's exactly how we used to build houses.  Which isn't to say we are just winding the clock back a few hundred years, we need all the benefit of the good and bad experiences we've had in the meantime and we need modern technology.

In a coming post we'll consider strimber materials and technologies in more detail. In the meantime I'd be interested to hear your ideas about how we should be building sustainable homes here in the UK.